The Collaborative International Dictionary of English v.0.48:

eyecup \eye"cup`\, n.
   A small oval porcelain or glass cup, having a rim curved to
   fit the orbit of the eye. it is used in the application of
   liquid remedies to eyes; -- called also eyeglass.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Eyeglass \Eye"glass`\, n.
   1. A lens of glass worn in front of the eye to assist vision;
      -- usually used in the plural, referring to a pair of
      lenses fixed together in a frame, and worn resting on the
      bridge of the nose, to improve the vision. A single
      eyeglass in a frame is called a monocle.
      [1913 Webster +PJC]

   2. Eyepiece of a telescope, microscope, etc.
      [1913 Webster]

   3. The retina. [Poetic]
      [1913 Webster]

   4. A glass eyecup. See Eyecup.
      [1913 Webster]

WordNet (r) 3.0 (2006):

eyeglass
    n 1: lens for correcting defective vision in one eye; held in
         place by facial muscles [syn: monocle, eyeglass]

Moby Thesaurus II by Grady Ward, 1.0:

57 Moby Thesaurus words for "eyeglass":
   Polaroid glasses, achromatic lens, astigmatic lens, bifocals,
   blinkers, burning glass, camera, cheaters, coated lens,
   colored glasses, concave lens, concavo-convex lens, condenser,
   contact lens, convex lens, dark glasses, divided spectacles,
   eyeglasses, eyepiece, glass, glasses, goggles, granny glasses,
   hand lens, harlequin glasses, horn-rimmed glasses, lens, lorgnette,
   lorgnon, magnifier, magnifying glass, meniscus, mini-specs,
   monocle, nippers, object glass, objective, objective prism, ocular,
   pair of glasses, peepers, prism, quizzing glass, reader, readers,
   reading glass, reading glasses, shades, specs, spectacles,
   sun-specs, sunglasses, telephoto lens, toric lens, trifocals,
   varifocal lens, zoom lens